Help, i was so stupid to install a module without backup and now is the screen blank


I have installed in my D8 the module Webform. After installing the screen went blank. When i go to admin/modules or /admin/config the screen stays blank. I have flush the cache, but no result. When i remove the Webform entry under modules i got an error : “The website encountered an unexpected error. Please try again later.”

Who can help? I have only acces to FTP and to phpmyadmin.


Drupal version: